A Corrective Action Implemenation Work Plan to implement corrective actions at five remedial units in the Building 207/231 Area, which comprises approximately 8 acres of land in the northeast portion of the Presidio located south of the Crissy Mars. Doyle Drive/Highway 101 north- and south-bound overpassess bisect the site. The purpose of the corrective actions are to achieve âclean closureâ for unrestricted reuse of the Site. Five different soil RUs and four co-located groundwater RUs require cleanup due to the presence above cleanup levels of total petroleum hydrocarbons (TPH) as gasoline, diesel, and/or fuel oil; volatile organic compounds (VOCs), and less-extensive occurrences of polynuclear aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), pesticides, and metals.